Why do cobras spit venom?

Cobras are one of the most fearsome species of snake in the world. Partly this is because of their venomous bite. Cobras, when they bite, have neurotoxic venom, which can cause all sorts of nasty effects, leading up to paralysis of the victim.

But that’s not the only reason cobras are feared. Some members of the cobra family are not only able to bite and inject venom into their prey, but are also able to spit venom from a distance. They do this because it allows them to hurt their prey without having to get close enough to suffer any damage. Spitting cobras can aim accurately from up to four feet away.

Venom acts best when it is in the bloodstream, so just coming into contact through the skin will usually not affect you. but if part of your skin is broken because of a previous wound, the venom can enter from there and reach the bloodstream, thereby having the same effect as snakebites.
In addition to that, venom that is spat can get into your eyes, which is what the cobra is targeting. Once it gets into the eye, it can cause burning and swelling up of the surface, and it can lead to permanent blindness if not washed out immediately.

Scientists have recently discovered the mechanisms behind this slippery survival tactic. Apparently, spitting cobras don’t actually spit the venom. The reaction causes the venom glands to contract, letting a spurt of venom exit the hole in their fangs. Not only does a spitting cobra rise up to ensure that the stream of venom hits you, scientists also discovered that they jerk their head a fraction of a second before the venom exits, thereby causing a spray of venom instead of simply a thin stream.

The spray of venom is theorized to be a better way to hit opponents, since at least one of the sprayed droplets is likely to hit the eye.